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With heightened national interest in energy conservation, different proposals have been made to improve the contribution of tires to fuel economy. California has enacted legislation that may lead to a state fuel economy standard for tires. This proposed low rolling resistance standard has been resisted by industry, which has raised concerns about the possible trade-offs in safety and tire wear life that might ensue. Even within California, there is concern about how reduced tire wear life could increase the state’s large stockpile of scrap tires. Congress requested a study by the National Academies to examine these issues and trade offs. The committee finds that reducing tire rolling resistance by 10 percent is feasible and would improve vehicle fuel economy by 1-2 percent if tires are properly inflated. If a 10 percent reduction in rolling resistance among replacement tires was achieved by reducing tread depth and certain changes in tread design, however, this could have negative consequences for safety and tire wear. The committee observes that tires are already on the market that achieve a 10 percent lower rolling resistance than the average tire, meet federal traction requirements, and have the wear characteristics that consumers prefer, albeit at a modest cost premium. The committee recommends that Congress provide the U.S. Department of Transportation with resources to provide consumers information about rolling resistance.